As a nerd, I have a (usually socially unacceptable) impulse to offer 16 possible ways that some plan could go wrong. It's fun, and on occasion useful. It seems very possible to me that your impression of "the state of bioethics" comes from a selection effect, where bioethecists show off their coolest objections to an obviously good thing.
Actually, in engineering school, I learned the same notion -- "shoot lame puppies early". It's a good plan to look for every possible (for a reasonably narrow definition of "possible") way your design could fail before you move further.
All I'm trying to say is that just because these philosophers are talking about cases that probably don't matter doesn't mean that no-one should think about them. On the very small chance that they do matter, the payoffs for having thought about them are large.
I've tended to think that bioethics is maybe the most profoundly useless field in mainstream philosophy. I might sum it up by saying that it's superficially similar to machine ethics except that the objects of its warnings and cautions are all unambiguously good things, like cognitive enhancements and life extension. In an era when we should by any reasonable measure be making huge amounts of progress on those problems—and in which one might expect bioethicists to be encouraging such research and helping weigh it against yet another dollar sent to the Susan G. Komen foundation or whatever—one mostly hears bioethicists quoted in the newspaper urging science to slow down. As if doubling human lifespans or giving everyone an extra 15 IQ points would in some way run the risk of "destroying that which makes us human" or something.
Anyway, this has basically been my perspective as a newspaper reader—I don't read specialty publications in bioethics. And perhaps it should come as no surprise that bioethics' usefulness to mainstream discourse would be to reinforce status quo bias, whether that's a true reflection of the field or not. In any case, it was a welcome surprise to see an interview in The Atlantic with Allen Buchanan, who apparently is an eminent bioethicist (Duke professor, President's Council on Bioethics), entirely devoted to refuting common objections to cognitive enhancement.
Some points Buchanan makes, responding to common worries: